4.2 Hoisting & Lifting Equipment

HVAC/R mechanics use a variety of mechanical lifting devices to move heavy equipment into position. Understanding the operating principle, rated capacity, and limitations of each device is essential to safe and efficient work.

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⚙️Mech. Advantage 🔄Pulley Systems 🏗️Cranes 📊Load Charts ⛓️Hoists 🔩Jacks 🪛Pry Bars

4.2.1 Principles of Mechanical Advantage

Most hoisting and lifting devices operate on the principle of mechanical advantage — using pulleys, levers, or screws to multiply an applied force so that a smaller input force can move a larger load.

Simple Pulley Systems

A single fixed pulley only changes the direction of force — mechanical advantage (MA) = 1.
A single movable pulley provides MA = 2; a 500 N input can lift a 1,000 N load.
A block-and-tackle system uses multiple pulleys to achieve higher MA values — the operating principle of a chain fall.

Lever Principle

A pry bar acts as a Class 1 lever: effort at the long end × its distance from the fulcrum = load × its shorter distance.
Allows a mechanic to shift heavy equipment with modest effort for small increments of movement.
Mechanical advantage increases as the effort arm gets longer relative to the load arm.

Screw Jack Principle

Hydraulic and mechanical screw jacks convert rotational motion into linear force.
The pitch of the thread determines the mechanical advantage.
A fine-pitch screw provides higher MA but requires more turns to achieve the same lift height.

4.2.2 Cranes

Cranes provide the highest lifting capacity and reach. Mobile hydraulic truck cranes and pick-and-carry cranes are commonly used on HVAC/R installation projects to set rooftop units and chillers.

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Licensed Operator Required — Ontario All crane operations must be performed by a licensed crane operator in Ontario, in compliance with O. Reg. 213/91. Apprentices must not operate cranes without the required certification.

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Load Charts

Every crane has a manufacturer-issued load chart specifying its maximum rated capacity at different boom lengths and radii (horizontal distance from the centre of rotation to the load). The operator must consult and comply with the load chart before every lift. Never estimate crane capacity.

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Reading a Load Chart — 4 Steps

Determine the boom length required to reach the lift point.
Measure the lift radius — the horizontal distance from the crane's centre of rotation to the load.
Locate the intersection of boom length and radius on the chart.
The table value is the maximum allowable gross load, including the weight of all rigging hardware.

4.2.3 Hoists

Hoists are portable or fixed devices used for vertical lifting. They are commonly used to lift compressors, fan coil units, and other equipment into mechanical rooms or elevated positions.

Electric Chain Hoist

Motor-driven — provides fast, controllable lifting.
Widely used in permanent mechanical room installations and temporary lifting frames.
Always verify that the supporting structure (beam, trolley, or gantry) has adequate capacity for the load plus rigging weight plus a dynamic factor.

Manual Chain Fall (Chain Block)

Hand-operated chain wheel with a gearing system providing high mechanical advantage.
Portable — requires no power supply; ideal for confined spaces.
Typical capacities range from 0.5 to 10 tonnes.

Come-Along (Lever Hoist)

Uses a ratchet lever to tension a chain or wire rope.
Used for horizontal pulling and tensioning as well as short vertical lifts.
Commonly used to pull refrigeration units into tight spaces and to tension guy wires.
Not designed for sustained suspended loads — never exceed the rated capacity.

4.2.4 Jacks

Jacks are used to lift a load a short distance vertically from below. They are frequently used to raise heavy condensing units slightly for the installation of vibration isolation pads or curb frames.

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Common Jack Types in HVAC/R

Hydraulic bottle jack — compact, high-capacity; positioned directly under the load point.
Hydraulic floor jack — low-profile; rolls into position and lifts with a pump handle.
Mechanical screw jack — raises load by rotating a threaded rod; no hydraulic fluid required.

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Jacks Are Lifting Devices Only — Not Standing Supports Once a load is raised by a jack, immediately install rated blocking or cribbing before working under or alongside the equipment. Never rely on a jack alone to support a suspended load.

4.2.5 Pry Bars

Pry bars (crowbars) are used to shift heavy equipment small distances horizontally or to slightly raise a corner of a unit for levelling or insertion of lifting straps.

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Safe Use of Pry Bars

Always ensure the fulcrum surface is stable and will not slip or compress under load.
Never overload the bar — apply force steadily and do not extend the bar with a pipe (cheater bar) beyond its designed length.
Use only for small incremental movements; do not substitute for proper lifting equipment.
Keep hands and feet clear of the pinch point between the load and the floor.

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Protect Finished Surfaces Place a scrap piece of hardwood or a sacrificial plate under the pry bar fulcrum point to prevent damage to finished concrete floors, curb caps, or equipment housings.